Burr removing tool



June 26, 1945. D. A. JOHNSTON 2,379,238

BURR REMOVING TooL Filed March 2, 1942 2 Sheets-Sheet l ,l I U2U V1 n I l s s 3mm/1m DWIGHT A. JOHNSTON H June 26, 1945. D, A JOHNSTON 2,379,238

BURR REMOVING TOOL Filed March 2, 1942 2 Sheets-Sheet 2 DWIGHT A. -JoHNsToN @2% @Ma/aw Patented June 26, 1945 Dwight A. Johnston, Youngstown, Ohio, assigner to The McKay Machine Company, Youngstown, Ohio, a. corporation of Ohio j Application March 2, 1942, serial No. 433,661

Claims.

This invention relates to the art of manufacturing metal tubes and more particularly to an improved device for removing the burr thrown up in the interior of the tube when the same is Vmanufactured by a process in which the cleft edges of the preformed stock are butt welded together under pressure, which operation results in the formation of the burr as is well understood in the art. The tube making process, being essen-- tially a continuous process, presents substantial difliculties in the removal of the interior burr, particularly in tubes of vsmaller diameter.

It has been proposed to remove the interior burr in a continuous manner during the manufacture of the tube by employing either interior and exterior rolls to roll down the burr or xed or movable cutters inside .the tube to cut the burr away from the wall of the tube to leave the passage through the tube circular in cross section. In rolling, the excess metal is not removed but merely displaced and consequently the contour and area of the tube passage can not be accurately maintained. Also the excess metal after being flattened is not welded to the body of the tube and after cooling has a tendency to spawl off. In all interior burr removing tools employing cutters of which I am aware, the metal of thecontinuous burr is shaved off by either a iixed or a the shavingfinterferes with the operation of the tool mandrel supporting mechanism employed and is diiiicult to remove from the interior of the tube, particularly when the tube is of smaller diameter.

It is accordingly the primary object of the invention to provide an interior burr removing tool for a butt weld tube mill i-n which the excess `metal of the burr is removed from the wall of the tube whereby the cross-sectional shape and area oi.' the nished tube may be accurately maintained but in which the metal is removed in such rotating cutter in a more or less fixed length and manner that it does not jam the burr removing tool or its supporting mandrel and is readily removable from the interior of the tube. This is accomplished, in accordance with the invention, by employing an adjustable, but normally iixed, broach as the cutting tool to engage and remove the excess metal of the burr. The operation of the broach in this capacity is such that the metal is severed in small and successive increments by the respective lteeth of the broach. By employing a substantial number of teeth on the breach, it is possible to decrease the thickness of the individual severed sections to a value suilicient to or short shavings which readily by-pass the tool supported in the mandrel and pass along with the traveling tube.

Another object of the invention is the provision of an improved arrangement for mounting the interior burr removing tool mandrel in a tube mill. Normal practice is to mount the cutting tool in iixed relation on the mandrel and to tix the mandrel in relation to the seam cleft and seam of the tube being produced. 'I'he continuous burr therefore engages the cutting tool at the same point throughout the whole of the production run and, of course, the tool becomes dulled at this point and leaves a longitudinal ridge (or burr) in the tube. =To overcome this diiiiculty, the present invention provides a radius on the cutting edge of the burr removing edge which is substantially coincident with the radius of the passage through the tube being produced, and mounting the tool for ready adjustment about an axis substantially coincident with the longitudinal axis of the tube. Thus wear on the tool may -be readily distributed throughout its transverse extent without the necessity of shutting down the mill or removing stock from the same.

The above and other objects and advantages of the invention will become apparent from a consideration of the following detailed specification and the accompanying drawings wherein there is specifically disclosed a preferred embodiment of the invention.'

In the drawings:

Figure 1 is a broken longitudinal section through a tool andmandrel constructed in accordance with the present invention;

Figure 2 is a plan view oi the tool end of the mandrel of Figure 1;

Figure 3 is an outer end view of the mandrel; and

Figure 4 is a front elevation of the mandrel supportingy assembly.

Referring to Figure 1 of the drawings, reference numerals I0 and II. indicate the upper and lower rolls, respectively, of the next to the last stand oi a forming mill which may comprise part oi the complete tube mill, and the rolls of the last stand are indicated schematically at I2 and I3. In accordance with usual practice the welding apparatus, not shown, is positioned beyond the rolls I2 and I3 and, of course, the burr removing tool is positioned beyond the welding apparatus.

In accordance with usual practice the mandrel, designated herein by reference numeral I4, supporting the burr removing tool is carried at one cause the severed sections to break up into chips end by a plate I5 extending through the open 2 can c: me stoer adjacent the 1an mn stand or the forming mill. In accordance with the pre- 'ferred and illustrated embodiment of the present The longitudinal position oi the slide .I1is arranged to bekaltered by the rotation of a bolt 2l which has screw threaded connection with slide I1 and is held axially fixed with respect to a wall 22 of the member I3 through which it extends by the collars 23. f

' Block Il is provided with two laterally spaced forwardly extending lugs 24 through which extends a bolt 25 having threads on that portion thereof which is intermediate the lugs. Bolt 25 is provided with a shoulder to prevent its axial movement in one direction and a retainer 26 prevents its axial movement in the opposite direc-- tion. A transversely extending guideway 2l is formed in the block I6 parallel with the threaded portion oi the screw 25 and mounted on the threaded portion o! the screw and in screw threaded relation therewith is a follower 2l having a lug received Within the guideway 21. It should be apparent that rotation of screw 25 will move the follower 23 laterally of the machine.

Welded or otherwise suitably secured to the lower edge of plate I is a cylindrical socket 29 in which is rotatably received an end oi' the mandrel I4, the principal body of which, in the illustrated embodiment, consists of a metal tube. Mandrel I4 may project rearwardly of the socket 23 to be engaged by a peg 311 which prevents outward movement of the mandrel. The rear end oi the mandrel is provided with a tapered cap 3l to close oiI the passage through the tube and to assist the guiding of the stock about the mandrel assembly. Extending diametrically through the mandrel I4 adjacent the iront -encl of the plate I5 and rigidly secured in the mandrel by welding or otherwise is a lever 32 having a rounded outer end 33. Follower 28 has a socket to engage end 33 and it should be obvious that transverse movement of the follower 28 upon rotation of the screw will rotate mandrel I4 about its longitudinal axis.

To the outer end of mandrel tube I4 is secured a tool carrier 34 having supporting roller wells 35 and 36 to receive the supporting rollers 31 which are mounted on transversely extending shafts and which engage the lower portion of the interior surface of the tube wall to support the holder 34 in operative position within the welded tube. As is well understood in the art rollers 31 are backed by rolls engaging the outer surface oi' the tube.

The upper surface oi the holder 34 is provided with a longitudinally extending slot communicating, at its rear end, withfa transversely extending slot 3l. the side walls o! the latter having milled recesses in the bottom plane of the slots. tioned within the longitudinal slot is a broach 40 having a width substantially equal to the width of the slot and a depth somewhat greater than the depth of the slot so that-the cutting teeth of the same project above the upper surface of the holder 3l. Broach 40 has a longitudinal projection 4I at its rear Wall of the slot 3l as indicated in Figures l and 2. Extending vertically below `the broach 4D and entirely through the holder 34 are two spaced threaded Posis bores k4t2 in which are threaded headless setscrews i3. Suitable provision, not shown, may be made to lock the screws in adjusted position and it should be apparent that the screws provide an. arrangement whereby the vertical position and the angle of inclination oi the broach with respect to the longitudinal axis of the tube /may be readily adjusted. As indicated in Figure 3, the teeth of the broach 40 are curved to coincide with the circular curvature of the interior surface o! the tube being produced, the tube being designated by reference numeral 44.

Provision is made to conduct lubricant, cooling fluid, or cleaning air to the lbroach and this means may consist of a -bore 45 extending from the rear end of the holder 34 to the roller well 35. Bore 45 is, of course, in communication with, the passage through tube I4 and to conduct any of these iiuids into the tube, a suitable connection may be made into the tube I4, the iluid being supplied through a conduit 4B.

With the parts assembled as indicated in the drawings, the formed stock issues from the roll stand I0, il and passes over the holder 29 and mandrel I4 and through the welding throat of the machine Where the edges of the stock are butt welded together as is well understood in the art. In -this operation a `burr is thrownup both exterlorly and interiorly of the tube along the line of weld and as the interior burr is moved against the broach 40, it is removed in incremental sections or depths of cut by the successive teeth of the broach. Broach 40 is so constructed or is so adjusted (by means of set-screws 43) in the holder 34 that proper operation of the broach is attained. The operation of the broach is such that the excess metal of the burr is spawled or cut oil in small pieces which readily pass the outer end of the holder 34 and the roller 3l and pass' along with the tube away from the burr removing tool.

At intervals during the operation of the mill, the mandrel I4 may be rotated by adjustment of the screw 25 to present new cutting points of the teeth of broach 40 to the burr to distribute the wear transversely of the broach. The necessity nfor the adjustment is readily determined by an inspection of the completed product. ln this, manner a greater accuracy may be maintained in the interior shape and area of the tube without the necesslty of shutting down the mill. Distributed wear of the teeth of broach 4D may be compensated for by the adjustments 42, 43. The longiildinalladjutment 2I may be employed to center e ro ers with res c to tioned backing rolls. pe t the above men The above specifically described embodiment of the invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scopA (rights irtiltl'ention. Reference should therefore bi;

o e appended claims in scope of the invention. detel mining the What I claim is:

l. Burr removing apparatus for a con butt weld tube mill comprising a mandrel atrilalp to be received within the tube at the welding staten, means adapted to extend through the open cleft in the tube stock to anchor one end o! said mandrel, a burr removing tool carried by said mandrel adjacent the other end thereof said tool comprising a broach having a multiplicity of cutting teeth arranged to remove the burr in successive increments, said broach being convexed transversely, and means extending through said`open cleft to rotate said mandrel about its principal axis and to retain the mandrel in its adjusted position.

2. Burr removing apparatus for a continuous butt weld tube mill comprising a, hollow mandrel adapted to be received within the tube at the welding station, means adapted to extend through the open cleft in the tube stock to anchor one end of said mandrel and to conduct iiuid under pressure into said mandrel, a burr removing tool carried by said mandrel adjacent the other end thereof, said tool comprising a broach having a multiplicity of cutting teeth arranged to remove the burr in successive increments, said mandrel having means to conduct said fluid pressure tothe wall of said tube surrounding said broach.

3. Burr removing apparatus for a continuous longitudinal seam butt weld tube mill comprising a mandrel adapted tobe received within the tube at theA welding. station, means adapted to extend through the open cleft in the tube stock to anchor one end of said mandrel, said means including a swivel connection whereby said mandrel may be rotated about its principal axis, a burr removing tool carried by said mandrel adjacent the other end thereof and being convexed in the direction of the curvature of the tube, and means extending through said open cleft to rotate said mandrel and to retain the same in adjusted position.

4. Apparatus according to claim 3 further including adjustable means mounting said tool on said mandrel whereby a cutting edge' of said tool may be moved radially outward of said axis to compensate for general wear across the transverse cutting f ace of said tool.

5. Burr removing apparatus for a continuous butt weld tube mill comprising a hollow mandrel adapted to be received within the tube at the welding station, means adapted to extend through the open cleft in the tube stock to anchor one end of-said mandrel and to conduct fluid under pressure into the same, said means comprising a swivel connection whereby the mand'rel may be rotated about its principal axis, a burr removing tool carried by said mandrel adiacent the other end thereof, said tool having a convex cutting edge curved in the direction of curvature of the tube, a passageway in said mandrel to conduct fluid under pressure to the wall of said tube surrounding said tool, and means extending through said open cleft to rotate said mandrel and to retain the same in adjusted position.

6. Interior burr removing apparatus for a continuous longitudinal seam butt weld tube mili a longitudinally extending slot in one face of said holder, a broach positionedin said slot, a tapped bore through said holder at the bottom of said slot, said bore being adapted to receive `a setscrew whereby-at least a portion o1' said broach may be raised from the bottom of said slot, said mandrel being hollow whereby fluid under pressure may be conducted into the welded tube about said broach, and means extending through said open cleft to conduct said fluid into said mandrel.

7. Burr removing apparatus for a continuous longitudinal seanibutt weld tube mill comprising a mandrel adapted to be received within the tube at the welding station, means adaptedto extend through the open cleft in the tube stock to anchor one end of said mandrel, a holder secured to the other end of said mandrel, a longitudinally extending vslot in one face of said holder, a longitudinally extending recess in an end wall of said slot, and a broach positioned in said slot, said broach having an integral lug received within said recess.

8. Apparatus according to claim 7 further including a tapped bore in said holder adjacent the other end of said slot and depending from the bottom wall of said slot, said bore adapted to l receive a set-screw to engage the underside of said broach adjacent the end thereof opposite said lug. x i

9. In a continuous longitudinal seam butt weld tube mill, means toanchor the forward end of the burr removing tool carrying mandrel, said means comprising a plate adapted to be supported from the frame of the mill and to extend through the open clefiI of the tube stock, a longitudinallydisposed cylindrical socket carried by the lower edge of said plate and adapted to rotatably receive a portion of the mandrel, means engaging a portion of the mandrel at the forward end of said socket to prevent the withdrawal of said mandrelfrom said socket, a lever secured to said mandrel adja` said plate and adapted to rotatably receive a portion of the mandrel, said mandrel having'an aperture extending diametrically therethrough, a leverv wedged in said aperture, a screw held against axial movement and extending transversely above said mandrel, a follower on saidr screw, and means interconnecting said follower and lever whereby rotation of said screw will result in rotation of said man`drel about its principal axis.

DWIGHT JOHNBTN'.` 

